HAMMING.c

#include<stdio.h>
#include <curses.h>
//#include<conio.h>
 
int main() {
    int data[10];
    int dataatrec[10],c,c1,c2,c3,i;
    //clrscr();
    printf("Enter 4 bits of data one by one\n");
    scanf("%d",&data[0]);
    scanf("%d",&data[1]);
    scanf("%d",&data[2]);
    scanf("%d",&data[4]);
 
    //Calculation of even parity
    data[6]=data[0]^data[2]^data[4];
    data[5]=data[0]^data[1]^data[4];
    data[3]=data[0]^data[1]^data[2];
 
    printf("\nEncoded data is\n");
    for(i=0;i<7;i++)
        printf("%d",data[i]);
 
    printf("\n\nEnter received data bits one by one\n");
    for(i=0;i<7;i++)
        scanf("%d",&dataatrec[i]);
 
    c1=dataatrec[6]^dataatrec[4]^dataatrec[2]^dataatrec[0];
    c2=dataatrec[5]^dataatrec[4]^dataatrec[1]^dataatrec[0];
    c3=dataatrec[3]^dataatrec[2]^dataatrec[1]^dataatrec[0];
    c=c3*4+c2*2+c1 ;
 
    if(c==0) {
        printf("\nNo error while transmission of data\n");
    }
    else {
        printf("\nError on position %d",c);
        
        printf("\nData sent : ");
        for(i=0;i<7;i++)
            printf("%d",data[i]);
        
        printf("\nData received : ");
        for(i=0;i<7;i++)
            printf("%d",dataatrec[i]);
        
        printf("\nCorrect message is\n");
 
        //if errorneous bit is 0 we complement it else vice versa
        if(dataatrec[7-c]==0)
            dataatrec[7-c]=1;
        else
            dataatrec[7-c]=0;
        
        for (i=0;i<7;i++) {
            printf("%d",dataatrec[i]);
            
            return 0;
        }
    }
getchar ();
}